Liquid pump



A. F. VAN AMSTEL.

LIQUID PUMP.

APPLICATION FILED NOV. 18', 1920.

Patented Dec. 5, 1922.

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LIQUID PUMP.

APPLICATION FILED NOV. 18. 1920.

Patented Dec. 5, 1922.

3 SHEETS-SHEET 2.

A. F. VAN AMSIEL,

LIQUID PUMP.

APPLICATION EllLED NOV. 18, 1920.

Patented Dec. 5, 1922.

a SHEETS-SHEET Patented Dec. 5, 1922.

LIQUID PUMP.

Application filed November 18, 1920. Serial No. 424,956.

To all whom it may concern:

Be it known that I, ADRIAAN FREDERIK VAN AMs'rEL, a subject of theQueenof the Netherlands, residing at Amersfoort, in the Province ofUtrecht, in the Kingdom of the Netherlands, have invented certain newand useful Improvements in Liquid Pumps; and I do hereby declare thatthe following is a full,'clear, and exact description of the same.

This invention relates to a liquid-pump for internal combustion enginesand is characterized in that the discharge or outlet valve of thepressure space of the pump is not hydraulically but mechanically openedinwards with respect to said pressure space, and that the operation ofopening the outlet valve is performed in the interior of the pump bymeansof the pump piston or plunger or diaphragm or otherliquid-displacingmember.

The pump according to the invention is principally designed forinjecting liquid fuel or water into the combustion space ofinternal-combustion engines, and also may serve for other purposes.

The pump may be constructed in such a way, that during the pressurestroke of the same, the liquid fuel is first compressed in the pressurespace of said pump, i. e., is brought under pressure, before the outletvalve, at a certain point of the pressure stroke, is mechanicallyopened; and that the valve has returned into position on its seat beforethe pressure stroke is terminated. By this arrangement the injectioninto the motor is properly timed and the liquid in the pump from thebeginning to the end of the injection into the motor stands under a highpressure. When desired the injection may take place in a very shorttime, or it may be prolonged for some time, namely, whilst the crank ofthe. engine travels through a larger angle, and in both cases it maytake place powerfully and with a high speed, without putting too highrequirements upon the pump or its driving means. Moreover the injectionmay be effected with approximately constant pres;

sure, by choosing the dimensions in such a manner, that theliquid-displaclng-member, during the injection, displaces a quantity ofliquid nearly equal to that discharged by the outlet valve. Also thedimensions may be such, that during the njectlon, the

pressure in the pump is increased "or decreased.

Another embodiment of the invention con sists in that the outlet valveis closed after the pressure stroke of the pump has been completed.

In many internal-combustion engines the fuel must be injected under ahigh pressure in less than one fiftieth of a second and for this objectthe member driving the pump, in case the latter is of the ordinary knownconstruction, has to operate the pump piston with such tremendous speedand force, that the operation is practically equivalent to producinghundreds of hammer blows per minute. pression engines with surfaceignition, pressures in the pump barrel of 125 atmospheres and overhave'been registered, so that it will be clear what exceedingly. highrequirements said pumps and their driving mechanism have to fulfil ifsuch a pressure has to be produced hundreds of times per minute and-eachtime in one fiftieth of a second or even less. In thecase of a pumpaccording to the invention such pressure and even higher ones can beobtained withthe same or still higher frequency, without undulystressing the pump. and the driving mechanism. It is not necessary thatthe liquiddisplacing-member is operated with a high speed, since thepressure stroke of the pump may start a considerable time before thestarting of the injection. In order to render this possible, withoutproducing too high a pressure in the pump, the pressure space of saidpump is chosen so large, that 1n it the liquid may be sufficientlycompressed. For this object the pressure space of the pump need not tobe inconveniently large,

since for each power stroke only a small quantity of liquid is injectedand the compressibility of the liquid is sufiicient. If desired thedimensions may therefore be so chosen, that theliquid-disp1acing-member, displaces more liquid after the beginning ofthe active part of the pressure stroke than is injected into the motor;A portion of the liquid displaced therefore remains in the pressurespace and again expands during the return stroke or suction stroke ofthe liquid-displacing-member.

Pumps are known, with which, as is the case with a pump according to theinven- In the case of ordinary low-com tion, bymechanically opening theoutlet member, sufficient pressure already prevails in the liquid, toobtain a powerful injection into the engine immediately when said outletmember is opened, and in said pumps the outlet member may be againclosed, when a high pressure still prevails in the pressure space of thepump. This outlet member is however a slide, along which liquid isliable to leak and said slide is actuated from outside the pressurespace of the pump 50 that the device is moreover not so simple as thataccording to the invention and also lacks other advantages obtainedtherewith.

In order that the invention may be better understood, it is hereinafterfurther described with reference to the accompanying drawings, whichshow, by way of example,

a few embodiments of the invention and are not drawn to scale.

Fig. 1 shows, partly in section, a part of an engine, provided with apump according to the invention.

Figs. 2 and 3 are detail views showing parts of the pump according toFig. 1.

Figs. 4, 5 and 6 are detail views showing parts of the pump shown inFig. 1, said parts being placed in different operative positions.

Fig. 7 shows a modification of the parts aocordingto Figs. 4, 5 and 6.

Figs. 8, 9., 10, 1'1 and'12 are detail views relating to a construction,in which the .pump piston lifts the outlet valve by means of a bellcrank lever pivotally secured to said valve.

Fig. 13'shows a part of a pump plunger,

*which lifts the outlet valve by means of a pawl, pivotally secured tosaid outlet valve.

Fig. 14 shows, partly in section, a pump, the outlet valve of whichreturns in position on its seat after the pressure stroke is completed.

Fig. 15 is a section on the line AB in Fig. 14 of the lifting membersecured to the lower end of the outlet valve.

Fig. 16 illustrates, partly in section, another embodiment of a pump,the outlet valve of which is closed after the termina tion of thepressure stroke.

The engine cylinder 1, the water jacket 2 and the cylinder head 3 inFig. 1 are integral with each other. The-pump casing 4 is attached inand on the cylinder head 3 by means of bolts (not shown in the drawing)or in any other suitable way. The outlet valve 5 of the pump is at thesame time the member 6 is also the pump piston.

injection needle of the engine and the liftilrgig means of the pipe 7the casing 4 is in opeh communication with the vessel 8, in which thesuction valve 9 is arranged. The exact dimensions of the pressure spacecan therefore be obtained by choosing the dimensions of the vessel 8accordingly. The advantage .little room in and on the cylinder head, not

only because the supplementary pressure space is found in the vessel 8,but moreover since in the latter also the suction valve 9 may bearranged. The vessel 8 may be arranged at a suitable place out of theway. On the valve 5 the valve head 10 is arranged, in which head, aforked member 12 is pivotally disposed by means of shaft 11. Between theshanks of the forked member 12 a roller 13 is located, which isrotatable about the shaft 14, the ends of which latter project intocorresponding holes in the fork shanks. The pump piston 6 is notrotatable and is provided with a cam 15. The supply duct 16 ispreferably connected with a tank, in which the level of the liquid isabove that of the by-pass 17, so that the pressure space of thepump isfilled by gravitation and the air escapes from the pump through thepassage 17. Before putting the pump into action, the suction valve 9 isopened by means of the rod 18, and also the stop valve 19 is opened.Fig. 2 is a sectional plan view of the valve head 10, this section beingtaken through the centre of the bearings of the shaft 11 for the forkedpressure member and Fig. 3 is a section of the forked member 12 and theroller 13, going through the centres of the bores of the shafts 11 and14, and also an elevation of said shafts. The moving parts are shown inFig. 1 in the position which they occupy when the active part of thepressure stroke starts. During the first part of this active part of thepressure stroke the liquid is compressed in the pressure space of thepump, in consequence whereof the pressure increases. As soon as the cam15 abuts againstthe roller 13 (see Fig. 4) the opening of the valve 5starts, since the piston 6 continues its movement and the forked member12 rests against the pump casing 4,

Fig. 5 has been reached, the forked member 12 tilts to the left(rotating in clockwise dl-r rection) by the pressure of the valve spring20 and the valve 5 is closed. Since the pump piston 6, whilst the valve5 is open, continues its pressure stroke and the sectional area of thevalve seat and of the jet passage 21 is sufiiciently small, at themoment in which the valve 5 is closed, a pressure still prevails in thepump, higher than that in the engine cylinder 1, so that the injectionis effected powerfully and rapidly up to the end; and th j t collidesviolentlyagainst the collision ment caused by the piston 6 remainingun-' altered, in consequence whereof during themember 22, resulting in adispersion of the fuel in extremely small globules into the enginecylinder. The position occupied by the pump piston 6and the forkedmember 12 after the latter has been tilted, i. e., when the valve 5 isagain upon'its seat, is shown in Fig. 6. Soon afterwards the motion ofthe piston 6 isreversed and its suction stroke starts. As soon as thecam 15 permits, the forked member 12 is turned tothe right by the spring23 (inanti-clockwise direction), till it rests again on the casing 4, asis the case in the Figures 1, 4 and 5. During the first part of thesuction stroke the liquid in the pressure space of the pump expands,till the pressure in the supply duct 16 opens the suction valve 9 and aquantity of fuel is again drawn into the pressure space. The quantity offuel, injected into the motor through the jet opening 21, during theopen-- ing of the valve 5 may be controlled in a well known manner bythe governor of the engine, by hand or in both 'ways, e. g., by variablylimiting the suction stroke of the piston 6 or by keeping the suctionvalve 9 open during a shorter or longer part of the pressure stroke, sothat a portion of the fuel flows back from the pump into the supply duct16 or by both means. (If the suction valve 9 is held open during a partof the pressure stroke, the active part of the pressure stroke beginswhen the suction valve is closed.) In case the limits of the control arenot sufliciently spaced apart to attain the desired object, the volumewhich the pressure space of the pump is able to contain may be varied byinserting or removing balls 24 into or from the vessel 8. If more ballsare inserted into the vessel, so that the liquid capacity of thepressure space of the pump is decreased, then the pressure in thepressure space of the pump is raised higher, the com pressibility of theliquid and the displaceopening of the valve 5 more fuel is shot from thepump into the engine. On the other hand, by removing one or more balls24 from the vessel 8, a smaller quantity of fuel is injected.

In Figure 7 a modified form of the pump iston 6 and the bifurcatedmember 12 is illustrated. In the case of the construction shown inFigure 1, the centre of the shaft 11 of the forked member 12 lies at theright of the imaginary perpendicular line through the centre of theroller shaft 14, in consequence whereof the forked member turns to theleft immediately, when the valve is fully lifted, but in the case of theconstruction shown in Figure 7 the centre of the shaft 11 lies at theleft of the imaginary perpendicular line through the centre of theroller I shaft. Moreover the upper part of the cam is horizontal, sothat the valve 5 is kept open may serve, if the period of injection hasto be prolonged and if desired the sectional area of the seat of thevalve 5 and of the jet passage 21 may be so chosen that the piston 6,while the valve is open, displaces a quantity of fuel, approximatelyequal to that emerging through the valve, when the engine runs underfull load, so that the injection from beginning to the end takes placewith substantially constant pressure. Such an in jection may, e. g., bedesirable in the case of constant-pressure (Diesel) engines. It isobvious, that also the sectional area of the seat .of the valve 5 and ofthe jet canal 21 may be made smaller or larger, so that the pressure ofinjection'during such injection rises or falls.

The Figures 8, 9, 10, 11 and 12 relate to a pump, in which the valve 5is lifted by the piston 6 by means of a bell crank lever 26 secured tothe valve head 10 and pivotally mounted on the shaft 25. In Figure 8 theiston 6, the bell crank lever 26 and the valve liead 10 are shown in theposition, which they take at the beginning of the pressure stroke; andFigure 9 is an elevation of. the piston and the bell crank lever withthe shaft 25, seen from the right. The left arm 27 of the bell cranklever rests upon the piston and its right arm 28 has a groove madetherein (see Figure 9) through which a ridge 29 formed on the piston isadapted to reciprocate. The ridge 29 serves to keep the left arm 27 onthe level of the lifting edge of the piston 6, when said edge, as is thecase in the position shown in Figure 8, is at the left of the arm 27.During the active part of the pressure stroke, the liquid in thepressure space of the .pump is first compressed so that the pressure israised. As soon as the lifting edge of the piston abuts against theright arm 28 of the bell crank lever (see Figure 10) the opening of thevalve 5 starts. The continued motion of the piston causes the lifting ofthe valve 5 till the lower end of the arm 28 has reached the upper faceof the lifting edge of the piston (see Fig. 11). As soon as this hastaken place the lever 26 rapidly turns to the left in clockwisedirection) by the pressure of t e valve spring 20, so that the valve 5is closed. In Figure 12 the position is shown which the piston and thelever take after the valve is closed. ,Soon afterwards the motion of thepiston is reversed and as soon as the lifting edge of the piston allowsthe arm 28 to pass, the spring 30 presses the bell crank,

lever back in its position shown in Figures' 8, 9 and 10. The distanceindicated by the arrows is therefore the same in the Figures 8, 10 and12, but in Figure 11 it is increased by the lift of the valve 5.

In the design according to Figure 13 the valve 5 is lifted by the piston6 by means of a tooth 32 .pivotally mounted on the shaft 31 in the valvehead 10. The piston and the tooth are shown in the position, whichtheytake, when, during the pressurestroke, the piston starts to turn thetooth to the right (in anti-clockwise direction). Somewhat later duringthe pressure stroke the tooth abuts against the stepped lifting edge ofthe piston and. the valve is lifted until the lower face of the toothcomes free from the lift ing edge of the piston and the valve 5 is Iclosed. Thereupon the motion of the piston 6 is reversed and as soon asduring the suction stroke the lifting edge of the piston has passedsufficiently far to the left, the tooth is turned by the spring 33 tothe left (in clockwise direction) till it abuts against the stop 34,formed on the valve head 10, this being the position shown in Figure 13.The spring 33 is fastened to the pin 35 provided Within the valve head10.

In the case of the pump shown in Figure 14 no separate vessel 8 is usedand the suction valve 9 is located in the pump casing inter alia forengines, in which the pump is not placed on the top of the cylinder, asis the case with the pump according to Figure 1. The fuel is supplied tothe engine through the pressure passage 37. If the orifice of saidpassage leading into the engine is continuously open and in the conduitno non-return valve is applied, the liquid in the passage, after theinjection is terminated, is somewhat withdrawn by the piston 6 and doesnot remain in the forepart of the passage. Thereby the fuel is preventedfrom afterflowing into the cylinder when during the power stroke of theengine, the pressure in the cylinder sinks so that the liquid in thepassage 37 expandsand the walls of the passage contract. It is obviousthat in this way the injection'into the engine does not take place up tothe end under a high pressure. Thispressure in the ump sinks during, theopening of the out et valve 5,

until it is equal to the pressure in the engine cylinder. The injectionmayhowever start under a high pressure. The initial pressure may beincreased or decreased by inserting or removing one or more balls 24into or from the plug 38. Figure 15 is a section of the valve head 10 onthe line A-B in Figure 14. Of course the pump may also be provided witha stop valve 19 with an outlet passage 17, as is the case with the pumpaccording to Figure 16.

As may be understood, a pump, in which the liquid is passed from thepump into a passage 37, as is the case with the pump according to Figure14, may also be provided with one of the arrangements above described inorder that the outlet valve 5 may be closed before the .end of thepressure stroke.

The pump shown in Figure 16 differs from that according to Figure 14 inthat the piston does not lift the valve 5 by means of a roller, but bymeans'of a lever 39. At the end of the pressure stroke the piston 6first presses the right arm of the lever 39 upwards, till said leverabuts against the suction valve 9 and the continued motion of the piston6 causes the valve 5 to open. The valve 5 returns to its seat bythetension of the spring 20, as soon as the piston 6, after the startingofits suction stroke, has sufficiently sunk. The valve 5 may also beopened by the suction valve 9 by pressing the rod 18 downwards. This maybe of advantage, to fill the pressure space of the pump and the passage37 withliquid, before the pump is taken into use. i

In all the embodiments described the stop valve 19 and the suction valve9 may be opened, even while the engine is running, to let the air'escape fromthe pump. In this case it is necessary tostop the motion ofthe liquid-displacing-member 6, or to cause the outlet valve 5 to belifted during the pressure stroke. It is necessary that the outlet valve5 remain closed when the .stop valve 19 and the suction valve 9 areopened, since otherwise air might pass from the engine cylinder throughthe valve 5 into the pump. If in the case of the pumps shown in figures1,4 and 16 a check valve is applied in the conduit 37, it is obviousthat it is not necessary to eliminate the opening of the discharge valve5 when the stop valve 19 is opened for the purpose "of letting out airfrom the pump pressure space.

What I claim is: In a liquid-pump, in combination, a receptac e adaptedto provide a pressure cha that they take the position, which would be!therewithin, a discharge valve for said Within said pressure chamber,part of the pressure chamber adapted to be opened motion of saidliquid-displacing-member to toward the inside of said pressure chamber,said discharge valve for opening the same. 10

a liquid-displacing-member adapted to put In testmony whereof I heretoaffix my the liquid under pressure in saidpressure signature.

chamber While said discharge valve is closed, a

and means adapted to mechanically transmit A RIA REDERIK v n AMSTEL.

